femoral hernias bmj 2011

8/18/2019 Femoral Hernias BMJ 2011

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EASILY MISSED?

Femoral hernias

Henry Robert Whalen clinical research fellow 1

, Gillian A Kidd general practitioner 2, Patrick J O’Dwyer

professor of surgery

1

1University Department of Surgery, Western Infirmary, Glasgow G11 6NT, UK; 2Midlock Medical Centre, General Practice, Glasgow, UK

This is one of a series of occasional articles highlighting conditions thatmay be more common than many doctors realise or may be missed atfirst presentation. The series advisers are Anthony Harnden, university

lecturer in general practice, Department of Primary Health Care,University of Oxford, and Richard Lehman, general practitioner, Banbury.To suggest a topic for this series, please email us [email protected].

An overweight 65 year old woman visits her general practitioner

with discomfort in her right groin. On examination, the

suggestion of a reducible groin lump is noted. She is routinelyreferred to the surgical outpatient clinic with a possible diagnosis

of inguinal hernia. However, two weeks later and before her

surgical appointment, she again visits her general practitioner,

this time with vomiting, diarrhoea, and colicky abdominal pain.

She is immediately referred to the emergency department. An

abdominal radiograph shows small bowel obstruction. She is

admitted to the surgical ward with a diagnosis of obstructed

femoral hernia and has a small bowel resection and emergency

hernia repair.

What is a femoral hernia?

A femoral hernia is the protrusion of a peritoneal sac through

the femoral ring into the femoral canal, posterior and inferiorto the inguinal ligament. The sac may contain preperitoneal fat,

omentum, small bowel, or other structures.

Why is a femoral hernia missed?

Evidence is scarce as to the reason why femoral hernias are

often missed and present as emergencies. Patients may be aware

of groin discomfort or a groin lump, but they may not realise

its clinical importance and may be reluctant to seek medical

help. Initially some patients present to primary care with vague

symptoms including groin discomfort that may be attributed to

other disease such as osteoarthritis. As femoral hernias are

typically small, they may be easily missed on examination,

particularly in obese patients. Furthermore, owing to thedifficulty in clinically distinguishing groin hernias, femoral

hernias may be mistaken for inguinal hernias and referred for

surgical opinion on a non-urgent basis.3

In an emergency, patients may present with signs of bowel

obstruction, which include colicky abdominal pain, vomiting,

and abdominal distension. About a third of patients do not

complain of symptoms directly attributable to a hernia,4 and a

groin lump is not always present. Other diagnoses, such as

gastroenteritis, enlarged groin lymph node, diverticulitis, or

constipation, may be made in error.⇓Retrospective studies have observed that about 40% of hernias

causing symptoms of acute bowel obstruction are missed owing

to a lack of groin examination.5 6 The researchers concluded

that female patients and all patients with femoral hernia were

less likely to have a groin examination, despite signs of bowel

obstruction being noted.5

Why does this matter?

Although femoral hernias are less common than inguinal, they

are associated with higher rates of acute complication. The

cumulative probability of strangulation for femoral hernias is

22% three months after diagnosis, rising to 45% 21 months after

diagnosis, whereas the probability of strangulation for an

inguinal hernia is 3% and 4.5% respectively over the same time

period.7

Several studies have shown that acute femoral hernias and their

subsequent complications are associated with increased

morbidity and mortality.1 2 8-10 Examples of morbidity resulting

from acute presentation include increased rates of bowel

resection, wound infection, and cardiovascular and respiratory

complications.10 As elective femoral hernia repair has been

shown to be a relatively safe procedure (even in patients aged

over 80), it is generally accepted that femoral hernias should be

referred urgently and repaired electively.2 10 11 12

Missed femoral hernia at emergency presentation delays time

to surgery.5 One study has shown an increased likelihood of

bowel resection if surgery is undertaken more than 12 hours

after the onset of acute symptoms.13 Preoperative delay is clearly

Correspondence to: H R Whalen [email protected]

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BMJ 2011;343:d7668 doi: 10.1136/bmj.d7668 (Published 8 December 2011) Page 1 of 4

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How common are femoral hernias?

• About 5000 femoral hernia repairs are carried out in the United Kingdom each year

• Femoral hernias account for a fifth of all groin hernias in females but less than 1% of groin hernias in males

• The 40% of femoral hernias that present acutely are associated with a 10-fold increased risk of mortality1 2

linked with an increase in bowel resection, and this is associated

with mortality rates that are about 20 times higher than those

for patients having elective hernia repair (which would not

require a bowel resection).2

How is it diagnosed?

Clinical

Classically, femoral hernias present as mildly painful,

non-reducible groin lumps, located inferolateral to the pubic

tubercle. In contrast, inguinal hernias are found superomedially.

However, femoral hernias tend to move superiorly to a position

above the inguinal ligament, where they may be mistaken foran inguinal hernia. Differentiation of groin hernias on clinical

grounds is therefore unreliable, irrespective of the experience

of the examining doctor.14 In patients presenting electively, only

about 1% of groin hernias in males are likely to be femoral,

whereas the likelihood in females is about 20%. 1 Clinical

examination alone is inaccurate in differentiating groin hernia.14

Therefore in females, owing to the greater prevalence of femoral

hernia, consider all groin hernia to be femoral until proved

otherwise.

Femoral hernias may also present without a palpable lump and

with only vague symptoms of abdominal or groin pain.

However, symptoms may vary and there is a lack of evidence

to predict the likelihood of a particular symptom indicating thepresence of a femoral hernia. Patients may present later with

clinical features of bowel obstruction. Undertake a detailed

groin examination in all patients presenting with bowel

obstruction.

Investigations

Ultrasonography, magnetic resonance imaging, and computed

tomography (CT) have all been shown to be accuratein detecting

and differentiating groin hernias.

Ultrasonography is widely available, non-invasive, and highly

accurate in differentiating inguinal from femoral hernia—with

sensitivities and specificity of 100% being reported in two

studies.15 16 Its accuracy is, however, operator dependent.

Magnetic resonance imaging has been reported to be more

accurate than ultrasonography in detecting inguinal hernia.17

However, there is a lack of evidence for whether magnetic

resonance imaging is better than ultrasonography in detecting

and differentiating groin hernia. Therefore ultrasonography

should be the first choice for electively investigating suspected

groin hernia as it is more widely available, less costly, and

accurate.

CT scanning has been shown to be accurate in differentiating

groin hernias. One retrospective study reports the correct

identification of 74 of 75 hernias (28 femoral and 47 inguinal),

which were later confirmed at operation.18 This is broadly

comparable with the non-invasive modalities outlined above,but as there is a substantial radiation dose associated with CT

scanning, it should not be used electively for investigating

suspected groin hernia. In the acute abdomen, however, consider

CT as the first choice for investigating suspected small bowel

obstruction in the presence of a negative clinical examination.

How is it managed?

In males, a groin hernia suspected as being femoral on clinical

examination requires urgent referral, due to the risks of acute

complications outlined above. All groin hernia in females should

be urgently referred for assessment.

Electively, both open and laparoscopic repair using mesh have

significantly lower recurrence rates than repair using sutures

only.1 Open repair has the advantage that it can be performed

under local anaesthetic. No evidence suggests superiority of

either method in the acute setting.

Some research has suggested that femoral hernias may be

overlooked during repair of suspected inguinal hernias.19 So

during surgical repair of all groin hernias examine the femoral

canal if an obvious inguinal hernia is not observed.

Contributors: The authors jointly developed the idea for the manuscript,

interpreted data from the literature, and drafted and revised the

manuscript. All authors approved the final version. PJO’D is the

guarantor.

Competing interests: All authors have completed the ICMJE uniform

disclosure form at www.icmje.org/coi_disclosure.pdf (available on

request from the corresponding author) and declare: no support from

any organisation for the submitted work; no financial relationships with

any organisations that might have an interest in the submitted work in

the previous three years; no other relationships or activities that couldappear to have influenced the submitted work.

Provenance and peer review: Commissioned; externally peer reviewed.

Patient consent not required (patient anonymised, dead, or hypothetical).

1 Dahlstrand U, Wollert S, Nordin P, Sandblom G, Gunnarsson U. Emergency femoral

hernia repair. A study based on a national register. Ann Surg 2009;249:672-6.

2 Nilsson H, Styliandis G, Haapamaki M, Nilsson E, Nordin P. Mortality after groin hernia

surgery. Ann Surg 2007;245:656-60.

3 McEntee GP, O’Carroll A, Mooney B, Egan TJ, Delaney PV. Timing of strangulation in

adult hernias. Br J Surg 1989;76:725-6.

4 Hjaltson E. Incarcerated hernia. Acta Chir Scand 1981;147:263-7.

5 Nilsson H, Nilsson E, Angeras U, Nordin P. Mortality after groin hernia surgery: delay of

treatment and cause of death. Hernia 2011;15:301-7.

6 Kjaergaard J, Nielsen M, Kehlet M. Mortality following emergency groin hernia surgery

in Denmark. Hernia 2010;14:351-5.

7 Gallegos NC, Dawson J, Jarvis M, Hobsley M. Risk of strangulation in groin hernias. Br

J Surg 1991;78:1171-3.

8 Malek S, TorellaF, EdwardsP. Emergency repair of groin hernia:outcomeandimplications

for elective surgery waiting times. Int J Clin Pract 2004;58:207-9.

9 AndrewsNJ. Presentationand outcomeof strangulatedexternalherniain a districtgeneral

hospital. Br J Surg 1981;68:329-32.

10 Alvarez J, Baldonedo R, Bear I, Solis J, Alvarex P, Jorge J. Incarcerated groin hernias in

adults: presentation and outcome. Hernia 2004;8:121-6.

11 Kemler M, Oostvogel J. Femoral hernia: is a conservative policy justified? Eur J Surg

1997;163:187-90.

12 Glassow F. Femoral hernia: review of 2105 repairs in a 17 year period. Am J Surg

1985;150:353-6.

13 Tanaka N, Uchida N, Ogihara H, Sasamoto H, Kato H. Clinical study of inguinal and

femoral incarcerated hernias. Surg Today 2010;40:1144-7.

14 Hair A, Paterson C, O’Dwyer PJ. Diagnosis of a femoral hernia in the elective setting. J

R Coll Surg Edinb 2001;46:117-8.

15 Bradley M,Morgan D,Pentlow B,Roe A. Thegroin hernia—anultrasounddiagnosis. Ann

R Coll Surg Engl 2003;85:178-80.

16 Djuric-Stefanovic A, Saranovic D, Ivanovic A, Masulovic D, Zuvela M, Bjelovic M, et al.

The accuracy of ultrsonography in classification of groin hernias according to the criteria

of the unified classification system. Hernia 2008;12:395-400.17 Van de Berg J, de Valois J, Go P, Rosenbusch G. Detection of groin hernia with physical

examination, ultrasound and MRI compared with laparoscopic findings. Invest Radiol

1999;34:739-43.

18 Kitami M, Takase K, Tsuboi M, Hakamatsuka T, Yamada T, Takahashi S. Differentiation

of femoral and inguinal hernias on the basis of anteroposterior relationship to the inguinal

ligament on multidimensional computed tomography. J Comput Assist Tomogr

2009;33:678-81.



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Key points

• Femoral hernias are more common in females and in people aged over 65 years and are associated with higher rates of complicationssuch as strangulation

• Emergency surgery for femoral hernia is associated witha 10-fold increased riskof mortality, which is further increased by preoperativedelays

• Clinical examination is unreliable in differentiating femoral from inguinal hernia

• Refer all females with groin hernia for urgent assessment and management

• Examine the groins of all patients presenting with signs of small bowel obstruction

• Ultrasound is the first line elective investigation for suspected uncomplicated groin hernia, but in acute small bowel obstruction, CTscanning is first choice

19 MikkelsenT, Bay-NielsenM, KehletH. Risk offemoralhernia afteringuinalherniorrhaphy.

Br J Surg 2002;89:486-8.Cite this as: BMJ 2011;343:d7668

© BMJ Publishi ng Group Ltd 2011



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Figure

Inguinal hernias are usually reducible and above the inguinal ligament. Femoral hernias are often irreducible and belowthe inguinal ligament. Adapted with permission from Ellis H. Clinical anatomy . 6th ed. Blackwell Scientific, 1977



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femoral hernias bmj 2011

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